Pellet mill die and method of forming same



A ril 21, 1964 J. MITCHELL 3,129,458

,PELLET MILL DIE AND METHOD OF FORMING SAME I Filed May 15, 1961 INVENTOR. JflC/f L. MITCHELL United States Patent 3,122,453 PELLET MILL DIE AND METHUD 0F FOG SAME Jack L. Mitchell, Muscatine, Iowa, assignor to California Pellet Mill Qompan a corporation of California Filed May 15, 1961, Ser. No. 110,167

Claims. (Cl. 18-42) from both sides of the roll, with the result that more h the holes located in the central region of the die than toward the outer edges Under these conditions, the die will wear excessive escape of material from the lower edge portion of an extrusion roll, while material will be free to escape beyond the upper edge portion of such roll. ingly, in this type of mill, the wear on the die will be excessive over the lower rows of die holes pression side or" the die.

Additional objects of my invention will be brought out in the following description of a preferred embodiment of the same, taken in conjunction with the accompany- 3,l29,458 Patented Apr. 21, 1964 duction would normally be less, the degree of reduction of such resistance being roughly 1n accordance with the The PIOVlSlOIl of these counter-bores, produces a Working section 23 in a counter-bored hole of less length than the working section 25 of the holes in the central region of the dre, by an amount equal to the depth of the counter-bore, and by reason or" this, decreases the e 0 diameter at the compression ends thereof, said die being of uniform thickness between its compression side and its discharge side, an extrusion roll in extrusion relationship to and adapted for movement over the compression side of said die, the holes in said die traversed by an edge portion of said roll being counter-bored at their discharge ends to reduce the resistance to extrusion of material therethrough as compared to the resistance ofiered by others of said holes traversed by an intermediate portion of said roll.

2. A pellet mill die having a compression side adapted to be traversed by an extrusion roll, a discharge side, and a plurality oi die holes through said die from said compression side to said discharge side and of like diameter at the compression ends thereof, said die being of uniform thickness between its compression side and its discharge side, and the holes in said die traversed by an edge portion of such roll being counter-bored at their discharge ends to reduce the resistance to extrusion of material thereto as compared to the resistance offered by other of said holes traversed by an intermediate portion of said roll.

References Cited in the tile of this patent UNITED STATES PATENTS Webb Oct. 1, 1946 2,902,715 Norman Sept. 8, 1959 2,902,949 Meakin Sept. 8, 1959 FOREIGN PATENTS 205,253 Australia Jan. 3, 1957 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,129,458 April 21, 1964 Jack L. Mitchell It is hereby certified that error appears in the above numbered patent req'iiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 4, for "thereto" read therethro ugh Signed and sealed'i'this 29th day of June 1965.

EAL)

IEST W. SWIDER EDWARD J. BRENNflrh'ng Officer Commissioner of Patents 

2. A PELLET MILL DIE HAVING A COMPRESSION SIDE ADAPTED TO BE TRAVERSED BY AN EXTRUSION ROLL, A DISCHARGE SIDE, AND A PLURALITY OF DIE HOLES THROUGH SAID DIE FROM SAID COMPRESSION SIDE TO SAID DISCHARGE SIDE AND OF LIKE DIAMETER AT THE COMPRESSION ENDS THEREOF, SAID DIE BEING OF UNIFORM THICKNESS BETWEEN ITS COMPRESSION SIDE AND ITS DISCHARGE SIDE, AND THE HOLES IN SAID DIE TRAVERSED BY AN EDGE PORTION OF SUCH ROLL BEING COUNTER-BORED AT THEIR DISCHARGE ENDS TO REDUCE THE RESISTANCE TO EXTRUSION OF MATERIAL THERETO AS COMPARED TO THE RESISTANCE OFFERED BY OTHER OF SAID HOLES TRAVERSED BY AN INTERMEDIATE PORTION OF SAID ROLL. 